Chip electronic components include components of which elements are covered with protective member. This kind of components are manufactured in this way: first, form conductive film by electroplating method on the surface of a base, second, work the conductive film to form an element section, then cover the element section with a protective member.
This type of chip electronic component uses a protective member formed by applying insulating paste. This paste-applying method has not posed any serious problems in rather large size components so far.
However, small size components, of which dimensions are 1.0×0.5 mm and 0.6×0.3 mm, are recently commercialized. In the near future, the smaller component such as 0.4×0.2 mm will be in the market.
Downsizing electronic components poses a problem that element-standing upright (so-called “Manhattan phenomenon”) phenomenon remarkably occurs because the protective member is formed round when paste is applied.
In addition to this problem, terminal electrodes formed on both the edges of the electronic component have dispersion in shape because of poor accuracy of the paste application. These problems adversely affect the properties of the electronic component.
For overcoming these problems, Japanese Patent Application Non-examined Publication No. H11-3820 discloses a method of forming a protective member by electrodeposition. However, when just the protective member of an electronic component is formed of electrodeposited film, the film attaches to everywhere of the element. Thus the electrdeposited film attached to both the ends of the element should be removed when terminal electrodes are formed. This removal work requires a lot of time, and blocks the productivity from increasing. The removal of the electrodeposited film possibly damages the conductive film formed on the base, then the properties are degraded or dispersed.
The foregoing prior art discloses a method of avoiding the attachment of the electrodeposited film to both the ends of the element, i.e., both the ends are covered by some jig, however, electrodeposition liquid tends to enter through a space between the element and the jig. Thus electrodeposited film is formed on both the ends of the elements, and the film prevents the terminal electrodes from being formed on both the ends. Further, if the protective member is formed by applying paste or by the electrodeposition method, the edge of the protective member becomes bumpy. Thus side face toward the element center of the terminal electrode becomes also bumpy, which adversely affect to mounting of the component or the properties of the component.
A thickness of the protective member becomes thinner as the electronic component is downsized, which weakens bonding strength between the protective member and the element.
For stabilizing the properties of electronic components, and increasing the mounting efficiency and the productivity of the electronic components, there are the following major objectives to be achieved. They are, efficient and accurate formation of the protective member, and increasing adhesion strength between the protective member and an element.